The ABCís About VOCís (PART I)

05/14/2007

Increasingly, consumers seeking building products with lower inherent toxicity are looking more closely at ingredients and asking tough questions. In the architectural coatings industry, those ingredients that have the potential to be hazardous are commonly classified as volatile organic compounds, or known better by their acronym, VOCs.

Increasingly, consumers seeking building products with lower inherent toxicity are looking more closely at ingredients and asking tough questions. In the architectural coatings industry, those ingredients that have the potential to be hazardous are commonly classified as volatile organic compounds, or known better by their acronym, VOCs.

In the workaday world of bucolic upstate New York, the term VOC seems unfamiliar to most consumers and even most construction industry personnel. But just as ignorance of the law does not exempt one from it, ignorance of the effects of VOCs doesn’t exempt one from their effects. Additionally, products that are either touted as “Low-VOC” or even “Zero VOC”are not necessarily free from potentially harmful ingredients. Some contain what are classified as Hazardous Air Pollutants or HAPs, and these chemical compounds can differ from VOCs.

In this article, Andy Pace, of Safe Building Solutions in Waukesha, WI and I will take a brief, focused look at what VOCs and HAPs are, and how they are formed. Because the subject of VOCs and HAPs is so massive and the science of their effects is so young, our discussion will focus on just a few of the main elements that can contribute to lowered indoor air quality (IAQ).

Understanding the effects of HAPs and VOCs on human health is important because we spend about 90% of our time inside increasingly tight structures where accumulations of interactive chemicals can cause concentrations of pollutants that can be as much as 50 to 100 times greater than outdoor air.

The importance of this in the paint and coatings industry was brought sharply into focus for me as I was writing this month’s column. I was referred to a couple who were building a spacious new luxury home. They had made it a point to investigate, specify, and ensure that all the materials that were used throughout the process were as non-toxic and free of harmful chemicals and the potential for outgassing as possible. In this process, they repeatedly surpassed the knowledge base of their architect and design-build team. The possibility that during the completion phase of the project they could sabotage their vigilant work by installing paints and finishes that could degrade the quality of their indoor air was a thought that never crossed their minds. This is ironic, because architectural coatings can be a massive source of indoor pollution given the surface area that they occupy. We must also remember that they are routinely used for recoating.

When I began to educate them as to how the dynamics of toxicity work when many conventional products are applied to absorptive substrates such as gypsum board, they became eager to learn of alternatives and anxious to learn how to correct mistakes that they had already made.

What are VOCs, exactly, and why all the fuss?

The Indoor Environment Department (IED) Staff of the Environmental Energy Technologies Division at Lawrence Berkeley National Laboratory (a division of our EPA) defines VOCs broadly as “chemical compounds based on carbon chains or rings with vapor pressures greater than 0.1 millimeters of mercury at room temperature. These compounds typically contain hydrogen and may contain oxygen, nitrogen and other elements.”

Prior to this century, US government tests that examined chemicals and passed laws that restricted their inclusion in architectural coatings, focused primarily on the damage that these chemicals created in outside air.

During the second half of the 90s however, the EPA’s National Risk Management Research Laboratory (NRMRL) began to investigate how architectural coatings could contribute to indoor air pollution and harm human health. They began compiling research from tests of conventional alkyd and latex products, as well as Low-VOC and Zero-VOC latex coatings. An important aspect of their research was simply to devise tests that would be meaningful. Interestingly, a solution to this question became apparent when they applied coatings to different substrates and then monitored their behavior.

What they learned was that the emission behaviors of chemicals were very different when coatings were applied to non-absorptive substrates such as glass, aluminum, and stainless steel, than they were when they were applied to the absorptive surfaces that they are typically used on such as wood and gypsum board. Naturally, they concluded that to be meaningful their tests needed to reflect the behavior of coatings on the surfaces that they are normally applied to.

Part of the reason why this research is important, is that architectural coatings are commonly deployed in commercial spaces such as schools, hospitals and medical facilities, day care centers, offices, hotels, and other public spaces in which continuous occupation is the rule. Especially in the case of medical facilities, patients with compromised immune systems may be subjected to hazardous air pollutants that can pose a threat.

A few key points summarized from recent government research are as follows:

• Alkyd coatings can contain as many as 100 different VOCs.

• The majority of emissions from latex paints occurs after the coating has dried.

• It may take as long as 3.5 years for some VOCs to be released from gypsum board.

• Some paints marketed as “low-VOC” may still emit significant quantities of HAPs.